The present invention generally relates to automatic fluid dispensing devices, and, more particularly, to pump-type spray dispensers of the kind generally utilized for dispersing fragrances or insecticides into the atmosphere.
Numerous types of automatic devices are utilized in public facilities for dissipation of malodoriferous aromas. For example, one type of odor control device utilizes a powered fan to assist in the movement of air over a tub or container which is filled with odor-covering material, such as an odoriferous gel. Such an odor control device is described in U.S. Pat. No. 4,830,971. Moreover, pressurized aerosol containers have been used with automatic dispensers to spray fragrances and/or insecticides into the atmosphere at periodic time intervals. One such metered aerosol fragrance dispenser is described in U.S. Pat. No. 5,038,972, wherein a segmented gear and cam arrangement are used for activating the spring-loaded spray button of the aerosol container.
A different type of pressurized aerosol can dispenser actuating mechanism is shown in U.S. Pat. No. 3,589,563 issued to Carragan et al. In that patent, a spring-biased actuating lever arm is pivotally mounted for rocking movement about a stub shaft, having a cam follower at the free end. The cam follower rides upon the surface of a snail-shaped cam which is integrally formed with a motor-driven gear arrangement. Rotation of the gear arrangement causes the cam follower to reach a point of drop-off on the cam, wherein the actuating arm swings downwardly under the force of the biasing spring to exert sufficient force on the cap of the aerosol container to overpower the container spring valve and initiate discharge. Continued rotation of the cam gear causes the cam follower to ride up along the snail-shaped portion of the cam and release the aerosol container cap, which completes the discharge cycle. A similar cam/lever arm actuating mechanism is used with a non-aerosol plunger or pump-type spray container in U.S. Pat. No. 4,235,373 issued to Clark.
However, several problems have occurred when the cam/lever-type actuating mechanism is used with a pump-type spray container. Non-pressurized pump-type fluid spray containers are normally designed for manual operation using a person's finger. Therefore, with an automatic pump-type spray dispenser, a strong biasing spring is required to quickly force the actuating lever arm downwardly for proper operation of the spray pump. For example, if the spray head of the container was slowly depressed into the container, little or no spray dispersion would occur.
Hence, each time the lever arm drops off the high point of the cam and impacts the container spray head, a loud noise is produced. If the spray dispenser is used in a room which people occupy continuously, then this "slapping" noise, occurring approximately every 15 minutes, becomes very annoying. Moreover, if the fluid dispenser is used in a room infrequently occupied by people, such as a public washroom, then the loud slap noise, which occurs suddenly in an otherwise quiet room, is quite startling. In either case, the loud slap noise produced when the lever arm contacts the spray head is a very undesirable characteristic of the pump-type spray dispensers known in the art.
Furthermore, a significantly high impact force is produced when the lever arm contacts the spray head and fluid pump mechanism of the container. This high impact force has been shown to reduce the operating life of the fluid dispenser pump and/or the spray head. Similarly, the high impact force has produced an undesirable amount of wear and tear on the cam/lever arm actuating mechanism assembly itself, as well as vibration of the electronic components which operate the actuating mechanism. In any event, the reliability of the spray dispensing devices of the prior art is affected.
A need, therefore, exists to find a practical, low-cost solution to reduce the high impact force of the lever arm on the fluid container of a pump-type spray dispenser and, accordingly, the noise produced thereby.